title: Quantitative assessment of lipiodol deposition after chemoembolization: comparison between cone-beam CT and multidetector CT.
abstract: OBJECTIVE
  To evaluate the ability of cone-beam computed tomography (CBCT) performed directly after transarterial chemoembolization to assess ethiodized oil (Lipiodol) deposition in hepatocellular carcinoma (HCC) and compare it with unenhanced multidetector computed tomography (CT).
  
  
  METHODS
  Conventional transarterial chemoembolization was used to treat 15 patients with HCC, and CBCT was performed to assess Lipiodol deposition directly after transarterial chemoembolization. Unenhanced multidetector CT was performed 24 hours after transarterial chemoembolization. Four patients were excluded because the margin of tumor or area of Lipiodol deposition was unclear. The image enhancement density of the entire tumor and liver parenchyma was measured by ImageJ software, and tumor-to-liver contrast (TLC) was calculated. In addition, volumetric measurement of tumor and Lipiodol was performed by semiautomatic three-dimensional volume segmentation and compared using linear regression to evaluate consistency between the two imaging modalities.
  
  
  RESULTS
  The mean value of TLC on CBCT was not significantly different from TLC on multidetector CT (337.7 HU ± 233.5 vs 283.0 HU ± 152.1, P = .103).The average volume of the whole tumor and of only the regions with Lipiodol deposition and the calculated average percentage of Lipiodol retention on CBCT were not significantly different compared with multidetector CT (tumor volume, 9.6 cm(3) ± 11.8 vs 10.8 cm(3) ± 14.2, P = .142; Lipiodol volume, 6.3 cm(3) ± 7.7 vs 7.0 cm(3) ± 8.1, P = .214; percentage of Lipiodol retention, 68.9% ± 24.0% vs 72.2% ± 23.1%, P = .578). Additionally, there was a high correlation in the volume of tumor and Lipiodol between CBCT and multidetector CT (R(2) = 0.919 and 0.903).
  
  
  CONCLUSIONS
  The quantitative image enhancement and volume analyses demonstrate that CBCT is similar to multidetector CT in assessing Lipiodol deposition in HCC after transarterial chemoembolization.
authors.affiliation: Russell H. Morgan Department of Radiology and Radiological Science, Division of Vascular and Interventional Radiology, The Johns Hopkins Hospital, Sheikh Zayed Tower, Suite 7203, 1800 Orleans Street, Baltimore, MD, 21287.
authors.forename: Rongxin
authors.initials: R
authors.lastname: Chen
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Geschwind
authors.forename: Zhijun
authors.initials: Z
authors.lastname: Wang
authors.forename: Vania
authors.initials: V
authors.lastname: Tacher
authors.forename: MingDe
authors.initials: M
authors.lastname: Lin
mesh_terms: D006528:Carcinoma, Hepatocellular / Q000098:blood supply / Q000000981:diagnostic imaging* / Q000188:drug therapy; D016461:Chemoembolization, Therapeutic; D054893:Cone-Beam Computed Tomography; D003287:Contrast Media / Q000008:administration & dosage; D004998:Ethiodized Oil / Q000008:administration & dosage; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D016014:Linear Models; D008113:Liver Neoplasms / Q000098:blood supply / Q000000981:diagnostic imaging* / Q000188:drug therapy; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography; D011237:Predictive Value of Tests; D011857:Radiographic Image Interpretation, Computer-Assisted; D012189:Retrospective Studies; D047368:Tumor Burden; D057188:Workflow
chemical_list: D003287:Contrast Media; D004998:Ethiodized Oil
keywords: 3D; CBCT; CT; HCC; HU; Hounsfield unit; ROI; TLC; computed tomography; cone-beam computed tomography; hepatocellular carcinoma; regions of interest; three-dimensional; tumor-to-liver contrast